Image : WHOI Partnership with King Abdullah University of Science and Technology (KAUST)

Many corals and other marine animals contain dinoflagellate symbionts that provide nutrition to the host from photosynthesis. These symbionts can be expelled from the host following exposure to elevated temperature or other stressors, resulting in a pale appearance or "bleaching." This partially bleached soft coral was observed in relatively deep waters (50 ft) during an August trip to the Red Sea. (Photo by Ann Tarrant, Woods Hole Oceanographic Institution)